Outer Dome Six was a dome-like structure on the surface of Kastria, from where Eldrad's obliteration module was controlled.
After Technic Obarl was frozen to death by the solar winds ravaging the planet's surface, Zazzka took over. King Rokon ordered that the module be detonated at nineteen spans, instead of the more secure twenty-five, due to fears that the dome would lose control over the craft as a result of Eldrad's destruction of the spatial barriers. (TV: The Hand of Fear)